The present application relates to a light detection device. More particularly, the present application relates to a light detection device for use in gene expression analysis, infectious-disease tests, gene analysis (e.g., SNP analysis), protein analysis, cell analysis or the like.
In recent years, research and development relating to gene analysis, protein analysis, cell analysis and the like have been widely conducted in various fields such as medical fields as well as the fields of drug design, clinical tests, foods, agriculture, engineerings, forensic medicine, criminal identification, etc. Especially, development and putting into practical use of the lab-on-chip technology have recently been under way, in which various reactions for detection and/or analysis of nucleic acids, proteins, cells, etc. are carried out in micro-scale channels or wells provided on a chip. The lab-on-chip technology has been drawing attention as a technique for easy measurement of biomolecules and the like.
In such a lab-on-chip technology for performing reactions in micro-scale channels or wells provided on a chip, there is a keen request for development of a device with which various analyses can be carried out in actual scenes (e.g., medical sites). Thus, how to realize the downsizing of device is an inevitable problem to be solved. Therefore, in order to achieve efficient detection and/or analysis in a compact device, it may be necessary to make various ingenuities as to the chips and devices used, the detecting and/or analyzing methods adopted, and the like.
For example, Japanese Patent Laid-open No. 2008-151770 proposes a microchannel chip with which reductions in size and manufacturing cost can be achieved. In the microchannel chip, specifically, a reagent in mixture with a heat-soluble binder is carried at predetermined positions in the microchannels. Then, the heat-soluble binder begins to be dissolved at the predetermined positions by a temperature rise from the temperature at which a specimen is introduced, whereby the dissolving treatment and the mixing treatment can be carried out efficiently. Further, the subsequent reaction treatment and analyzing treatment can be carried out at the same positions, so that the number of treatment positions on the microchannels can be reduced, leading to the reductions in size and cost.
Japanese Patent Laid-open No. 2007-139744 proposes a fluorescent polarimetric method by which a sample can be analyzed while using the sample in an amount of about 1/100 times that required in the methods according to the related art. The fluorescent polarimetric method, specifically, includes (1) a step of preparing a fluorescent probe molecule and a biomolecule, (2) a step of pouring the fluorescent probe molecule and the biomolecule into a microchannel of a lab-on-a-chip system so as to form a complex, (3) a step of irradiating the complex with polarized light and measuring the resulting fluorescent polarized light, and (4) quantifying the fluorescent polarized light and determining the degree of fluorescent polarization.
Japanese Patent Laid-open No. 2008-17779 proposes a lab-on-chip system by which nucleic acid replication, synthesis, reaction, detection, and the like can be carried out on a single substrate. Specifically, the substrate is provided thereon with a nucleic acid preparing section having a first electrode, a sample inflow section for inflow of a sample fluid into the nucleic acid preparing section, a reaction section having a second electrode which communicates with the nucleic acid preparing section though a channel, a medicinal liquid inflow section for inflow of a medicinal liquid into the reaction section, an outflow section for outflow of a fluid from the reaction section, a control circuit interconnecting the first and second electrodes, and a detection circuit connected with the second electrode.
Japanese Patent Laid-open No. 2007-187582 proposes a biochip which has detection electrodes including a working electrode, a reference electrode and a counter electrode, and a thin film transistor. With the biochip having these components, it is possible to realize a biosensing device which is small in weight, thickness, length, etc., high in performance, and low in cost. Further, the biochip can be mounted to and dismounted from a biosensor which has an ink jet head unit.